Model 455R, 455T Composite MTS/BTSC Subcarrier Receiver and Transmitter Operators Manual Rev 2.2 6/25/98 Data, drawings, and other material contained herein are proprietary to Cross Technologies, Inc., and may not be reproduced or duplicated in any form without the prior permission of Cross Technologies, Inc. When ordering parts from Cross Technologies, Inc., be sure to include the equipment model number, equipment serial number, and a description of the part. CROSS TECHNOLOGIES, INC.
Model 455R, 455T Composite MTS/BTSC Subcarrier Receiver and Transmitter Operators Manual TABLE of CONTENTS SECTION TITLE PAGE Warranty........................................................4 OPERATORS SAFETY CONSIDERATIONS................5 1 GENERAL INFORMATION ................................. 7 1-1. INTRODUCTION ........................................................... 7 1-2. SPECIFICATIONS .......................................................... 7 1-3. SAFETY CONSIDERATIONS .....................
TABLE of CONTENTS SECTION 3 TITLE PAGE OPERATION ................................................ 18 3-1. INTRODUCTION ........................................................... 18 3-2. APPLYING POWER ........................................................ 18 3-3. CONTROL SWITCHES .................................................... 19 3-4. STATUS CHANGES ....................................................... 19 3-5. ALARM INDICATIONS ................................................... 21 3-6.
WARRANTY This Cross Technologies product is warranted against defects in material and workmanship for one year from the date of shipment. During this period Cross Technologies will either repair or replace, at its option, products which prove to be defective. To obtain service under this warranty, this product must be returned to Cross Technologies at its address. Buyer shall pay all shipping charges to Cross Technologies, and Cross Technologies shall pay all charges for return shipment to buyer.
OPERATORS SAFETY CONSIDERATIONS General The general safety information in this documentation is for operating and servicing personnel. Specific warnings and cautions will be found throughout the manual where they apply and may or may not appear here. Safety Symbols ___________ _ WARNING _ ___________ WARNING symbols indicate a condition, practice or procedure that, if not properly performed or adhered to, could result in personal injury or loss of life.
OPERATORS SAFETY CONSIDERATIONS (Cont'd.) ___________ _ WARNING _ ___________ Danger From Loss of Protective Ground Upon loss of the protective ground connection, all accessible conductive parts can render an electrical shock. Do Not Remove Covers or Panels To avoid personal injury or shock, equipment should not be operated without covers or panels. Servicing Servicing instructions are for the use of qualified servicing personnel only.
Section 1 - GENERAL INFORMATION 1-1. INTRODUCTION. This manual contains information necessary for the installation, operation, testing and alignment of the Model 455 FM Subcarrier. The documentation for this product is divided into five sections as described below. Section 1.General Information: provides general information about this equipment, circuit description and specifications. Section 2.
TABLE 1-1 - SPECIFICATIONS System Characteristics: Subcarrier frequency range......Frequency agile from 1.0 MHz to 9.99 MHz in 10 kHz steps Frequency response..............±0.1 dB from 20Hz to 70kHz; ±0.5 dB from 70kHz to 120kHz Total harmonic distortion..........<0.05% at 1 kHz (De-emphasized, 30kHz bandwidth) Long term stability (6 months)....±0.1 dB at 25°C; ±0.25 dB, 0-50°C Channel spacing (minimum).......280 kHz for narrow deviation; 600 kHz for wide deviation Remote control input...............
TABLE 1-1 - SPECIFICATIONS (Cont'd.) Subcarrier output level.................75 to 300 mV P/P (adj.) Output impedance......................Bridging (≥3 kΩ) to 75Ω line Front panel adjustments/settings.............Deviation Subcarrier Level Subcarrier Frequency Deviation Range Wide/Narrow Channel On/Off Remote Control Mode / Alternate Frequency Front panel visual indications................Subcarrier Frequency Alarm and On/Off Status Overmodulation Remote Active Connector type.......................
1-4. GENERAL DESCRIPTION. The 455 Composite Subcarrier System is engineered to provide a transparent path for the complete MTS/BTSC composite signal over any video microwave system. With its extremely low distortion (less than 0.05% at 1kHz), flat frequency response from 20Hz to 120kHz, and outstanding long-term stability, the 455 has almost no measurable effect on stereo audio performance.
Section 2 - INSTALLATION 2-1. INTRODUCTION. This section contains instructions for installing and interfacing the Model 455 Composite MTS/BTSC FM Subcarrier. Included are initial inspection procedures, power and grounding requirements, line voltage selection, interface connections and instructions for repackaging the equipment. 2-2. INITIAL INSPECTION.
2-4. Power Requirements. The Model 455 requires a power source of 105V-130V 50-60Hz or 210V-250V 50-60Hz. Power consumption is: Transmitter.................. 24 VA maximum. Receiver..................... 20 VA maximum. 2-5. Line Voltage Selection. CAUTION Before connecting ac power to this equipment, make sure it is set to the line voltage of the power source. Also ensure that the common connection of the power outlet is connected to a protective earth contact.
Fig. 2.1 AC Connector 2-6. Power Cable. In accordance with safety standards, this equipment is supplied with a three conductor cable. When connected to an appropriate power line outlet, this cable grounds the equipment cabinet. 2-7. OPERATING ENVIRONMENT. The operating environment should be within the following limitations: Temperature........................ 0 °C to +50 °C Humidity........................... 95% maximum non-condensing Altitude........................... 3050 meters (10,000 ft.) ASL 2-8.
BTSC COMPOSITE MONITOR BASE BAND LOOP THRU INPUT OUTPUT BTSC COMPOSITE STEREO IN (XMT) OUT (RCV) SAP I NPUTS PRO N O C O N M C R M T ALM FIGURE 2-2 455 Rear Panel 2-10. Remote Control Interface Information. The 455 remote control input is capable of switching the unit to an alternate configuration which the user has pre-programmed (see Section 3-4 for set-up information).
75Ω. In multiple- unit operation, the input of units after the first is connected to the output of the preceding unit. Output - Composite output to microwave or satellite transmitter. In multiple unit operation, the output of all but the last unit connects to the input of subsequent units. Receiver: Input - Composite input from microwave or satellite receiver. In multiple-unit operation, the input of units after the first is connected to the output of the preceding unit.
Composite Monitor - This output connector provides a monitor point for the combined modulation signal resulting from the various input signals. The output impedance is 75Ω and should be terminated with 75Ω when measurements are being made.
2-14. REPACKAGING. If the equipment is to be returned to Cross Technologies for any reason, care should be taken in packaging. Call Cross Technologies for a Return Material Authorization (RMA) number. Enclose documents detailing reason for return, return address, name and telephone number of contact person. Original Packaging. It is preferable to use the original packaging if it was retained. Use care in packing, sealing and marking the container. Other Packaging.
Section 3 - OPERATION 3-1. INTRODUCTION. This section describes operation of the front panel controls. There are three operator switches, the LCD display and an alarm indicator. All functions for the equipment are controlled by these components. The functions are: 1.Turn the channel "on" or "off". 2.Set the frequency of the channel. 3.Select the "wide" or "narrow" deviation mode. 4.Setup these parameters for the remotely activated configuration.
3.The software version will be displayed. __________________ _Software Rev #.#_ __________________ 4.The present status of the channel is shown. The unit is now operational and ready for any changes the operator may desire. 3-3. CONTROL SWITCHES. 1.Program/Execute. Any change to the programming of the unit must be initiated by pressing the Program/Execute switch and completed by pressing the Program/Execute switch. 2.Cursor Movement - Horizontal.
Pressing the Up/Down switch (in either direction) will toggle the display to: __________________ _MODIFY REMOTE _ __________________ When the display indicates the configuration (local or remote) to be modified, press the Program/Execute switch. 2.Status of the selected configuration will be displayed. For example: __________________ _L 6.60MHz ON _ __________________ The display consists of: An initial letter indicates Local or Remote. The current frequency setting. The current ON/OFF status. 3.
4.Operate the Program/Execute switch. The display will now show the deviation setting (WIDE/NARROW): __________________ __________________ _WIDE DEVIATION _ or _NARROW DEVIATION_ __________________ __________________ If you wish to make a change, operate the vertical switch to toggle the status. When the display indicates the desired condition, press the Program/Execute switch a final time. At this time the changes you have made will become the new settings for the channel. 3-5. ALARM INDICATIONS.
Receiver: CXR ALM upon a drop in incoming carrier level beyond the squelch setting or the RF/IF section of the receiver is defective. AFC ALM if the incoming carrier is off frequency or if the frequency determining elements of the receiver are defective. CXR AFC if both alarms are present. CAUTION An annoying remote alarm can be disabled by turning the channel "off". If this is done there will be no alarm condition active to remind maintenance personnel there is a problem.
Audio is noisy, but sounds normal in other respects. Transmission path noise may be excessive. Check other system components, RF power, and antenna pointing. In non-video systems, if the subcarrier frequency is less than about 4.5MHz, the high pass filter in the receiver may not be set OUT. (See Section 5-17.) Audio sounds noisy. Tones, chirps, buzz, etc may also be present. Channel spacing may be too close.
Composite level and/or carrier deviation too high or low. LCD display blank. LCD display shows: NV Memory Error Receiver LCD display indicates a CXR alarm. Verify correct equipment impedances and terminations. Loss of power. Possible causes include blown fuse, incorrect line voltage selection, etc. (See Section 2-5.) A checksum error was found after reading the nonvolatile memory device.
Receiver LCD display indicates an AFC alarm. Any of the situations described above for a CXR alarm may, under some conditions, also cause an AFC alarm. The receiver may be tuned to a wide deviation channel which it is unable to track. LCD display is garbled or inconsistent with normal operation. Ribbon cable connecting display circuit board to the main circuit board may have come loose due to rough handling in shipping. See Section 5-13 to remove cover.
Section 4 - ADJUSTMENTS and OPTIONS 4-1. INTRODUCTION. This section describes operator adjustments and the selection of the internal options. For a discussion of the microprocessor-controlled functions (Channel ON/OFF, FREQUENCY and compandor IN/OUT) please refer to Section 3-4. For a discussion of line voltage selection, please refer to Section 2-5. The operator adjustments are located on the front panel on both the transmitter and receiver.
4-3. TRANSMITTER FRONT PANEL ADJUSTMENTS. NOTE:Prior to setting levels be sure transmitter is ON and set to proper frequency. See Section 3. 4-4. Level Adjustment (IF). Determine the desired subcarrier level for your specific system. The 455 Transmitter subcarrier level can be adjusted over the range of 75 mV to 300 mV p/p (approx. -8 TO -20 dB, 75Ω). A. Level Adjustment Without Video or Other Channels. If it is possible to set the subcarrier level with all other signals (i.e.
measuring instrument has a low impedance (i.e., 75Ω or 50Ω) it is necessary to connect the instrument to an isolated monitor point in order to prevent the additional load presented by the low impedance input from affecting the level to be measured. 2.With the measuring instrument properly tuned to the frequency of the channel to be adjusted, set the IF (subcarrier level) screwdriver adjustment on the front panel for the proper level for your system. 4-5. Deviation Adjustment (DEV).
The front panel DEV adjustment is provided to compensate for minor variations in incoming composite signal strength, and is not intended to provide for operation at deviations other than the 455's specified deviation. The deviation may be accurately set using either a modulation meter or a spectrum analyzer; choose the method you find most suitable. A. Deviation Adjustment Using a Modulation Meter. 1.
generator to provide a 10.396 kHz test signal at a 100% modulation level at both inputs. The pilot should be switched off for this procedure, and the SAP and PRO channels should also be OFF. 3.Temporarily disconnect the audio signal generator. Tune the spectrum analyzer to the frequency of the 455 subcarrier. Set the 455 Transmitter to the "narrow" deviation mode.
4-8. Squelch Adjustment. A.Tune the receiver to a compatible active channel. Presence of an Alarm indication and a CXR ALM display may indicate one or more of the following conditions: 1) No carrier is being received. 2) Squelch adjusted improperly. 3) The carrier receiver is malfunctioning. Whenever there is a CXR ALM (regardless of cause) there should be no audio output from the receive channel with the alarm. B.Squelch is factory set to operate if the incoming subcarrier amplitude drops below 25 mV p/p.
4-9. Composite Level Adjustment. A.Connect a high impedance AC Voltmeter across the BTSC Composite Out line. The audio equipment that will normally be connected to this line should remain connected while performing this measurement; if for any reason the level must be set in the absence of the connecting equipment, terminate the line with a precision 75Ω termination. B.
4-12. Input Highpass Filter. The 455 Receiver input circuitry includes a highpass filter that is designed to prevent high level video signals at the bottom of the baseband from overloading sensitive sections of the receiver. In applications where video is present on the baseband, this filter should always be strapped IN. In applications without video, where the entire baseband is dedicated to subcarriers, the filter should be jumpered in the OUT position. The input highpass filter selection is made with P8.
